4XZ0:
reference: Modification by covalent reaction or oxidation of cysteine residues in the tandem-SH2 domains of ZAP-70 and Syk can block phosphopeptide binding., Visperas PR, Winger JA, Horton TM, Shah NH, Aum DJ, Tao A, Barros T, Yan Q, Wilson CG, Arkin MR, Weiss A, Kuriyan J, Biochem J. 2015 Jan 1;465(1):149-61. doi: 10.1042/BJ20140793. PMID: 25287889

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